Concentrated fabric softening compositions

ABSTRACT

Concentrated fabric softening compositions are described which retain viscosity upon dilution in water. The compositions comprise cationic fabric softening actives, as well as a specific combination of emulsifiers and polymers. The present invention also encompasses a method for the softening of fabrics.

TECHNICAL FIELD

The present invention relates to fabric softeners. The compositionsaccording to the invention are concentrated fabric softeningcompositions which retain viscosity upon dilution.

BACKGROUND

Concentrated fabric softening compositions have been extensivelydescribed in the art, and one aspect which has often been discussed isthe viscosity of these concentrated compositions; indeed theseconcentrated compositions are typically extremely viscous and the priorart has often described means by which the viscosity of theseconcentrated compositions could be controlled or decreased. One aspectwhich has been much less dealt with is the viscosity of theseconcentrated compositions upon dilution; indeed it has been observedthat the viscosity of such concentrated compositions dramatically dropsupon dilution, and this viscosity loss is clearly undesirable,essentially in terms of consumer acceptance.

It is therefore an object of the present invention to provide aconcentrated fabric softening composition which has an acceptableviscosity in the concentrated form, and which retains acceptableviscosity after it has been diluted.

This technical problem was discussed in GB 2 007 734 which proposes touse a combination of a fatty quaternary ammonium salt having two longchain alkyl groups together with an oily substance.

Concentrated fabric softeners have been described for instance in EP 56695, EP 13 780, DE 26 31 114 and EP 60 003, and a process for thepreparation of concentrated fabric softening compositions is disclosedin EP-A-316 996.

SUMMARY OF THE INVENTION

It has now been found that the above object can be achieved byformulating a concentrated fabric softening composition comprising from10% to 35% by weight of a cationic fabric softening active, saidcomposition further comprising:

from 0.3% to 3% by weight of the composition of a linear fatty alcoholethoxylate of the formula RO(Etox)_(n), wherein R is a linear C₈ -C₁₈alkyl chain, and n representing the weighted average ethoxylation degreeis of from 3 to 35, or mixtures thereof;

from 0.5% to 6% by weight of the total composition of a nonionichydrophilic polymer, or mixtures thereof;

from 0% to 2% by weight of the total composition of a highly branchedfatty alcohol having from 8 to 18 carbon atoms, or mixtures thereof;

from 0% to 0.5% by weight of the total composition of a linear or cyclicpolydialkylsiloxane of the formula ##STR1## wherein R is a C₁ -C₅ alkylchain, and m is an integer of from 1 to 500, or mixtures thereof.

The present invention also encompasses a method for the softening offabrics, wherein the above concentrated compositions are diluted inwater before they are contacted with said fabrics in the rinse water.

DETAILED DESCRIPTION OF THE INVENTION

The compositions according to the invention are concentrated fabricsofteners; by concentrated, it is meant that the compositions comprisefrom 10% to 35% by weight of the total composition of a cationic fabricsoftening active or mixtures thereof, preferably 15% to 25%. Bycationic, it is meant any softening compound which is in cationic formin the concentrated softening composition. Suitable cationic fabricsoftening actives include

(i) acylic quaternary ammonium salts having the formula: ##STR2##wherein R₂ is an acylic aliphatic C₁₅ -C₂₂ hydrocarbon group which maybe interrupted by ester groups, R₃ is a C₁ -C₄ saturated alkyl orhydroalkyl group, R₄ is selected from R₂ and R₃, and A is an anion;rapidly biodegradable compounds of formula (i) where R₂, and possiblyR₄, are interrupted by ester groups, are disclosed in EPA 239 910;

(ii) diamido quaternary ammonium salts having the formula: ##STR3##wherein R is an acyclic aliphatic C₁₅ -C₂₂ hydrocarbon group, R₂ is adivalent alkylene group having 1 to 3 carbon atoms, R₅ and R₈ are C₁ -C₄saturated alkyl or hydroxyalkyl groups, and A⁻ is an anion:

(iii) diamido alkoxylated quaternary ammonium salts having the formula:##STR4## wherein n is an integer of from about 1 to about 5, and R₁, R₂,R₅ and A⁻ are as defined above.

(iv) quaternary imidazolinium compounds having the formula: ##STR5##wherein R₁ =C₁₅ -C₁₇ saturated alkyl, R₂ =C₁ -C₄ saturated alkyl, Z=NHor O, and A⁻ is an anion.

Examples of Component (i) are the well-known dialkyldimethylammoniumsalts such as ditallowdimethylammonium chloride (DTDMAC),ditallowdimethylammonium methylsulfate, di(hydrogenated tallow)dimethylammonium chloride, dibehenyldimethylammonium chloride.

Examples of Component (ii) and (iii) are methylbis(tallowamidoethyl)(2-hydroxyethyl) ammonium methylsulfate and methylbis(hydrogenatedtallowamidoethyl) (2-hydroxyethyl) ammonium methylsulfate, wherein R₁ isan acyclic aliphatic C₁₅ -C₁₇ hydrocarbon group, R₂ is an ethylenegroup, R₅ is a methyl group, R₈ is a hydroxyalkyl group and A is amethylsulfate anion; these materials are available from Sherex ChemicalCompany under the trade names Varisoft 222 R and Varisoft 110 R,respectively.

Examples of Component (iv) are1-methyl-1-tallowamino-ethyl-2-tallowimidazolinium methylsulfate and1-methyl-1-(hydrogenated tallowamidoethyl)-methylsulfate.

Other suitable fabric softening actives include the following amines,provided they are present in the concentrated softening composition in aprotonated form; such amines are of the formula: ##STR6## wherein n is 2or 3, preferably 2; R₁ and R₂ are, independently, a C₈ -C₃₀ alkyl oralkenyl, preferably C₁₂ -C₂₀ alkyl, more preferably C₁₅ -C₁₈ alkyl, ormixtures of such alkyl radicals. Examples of such mixtures are the alkylradicals obtained from coconut oil, "soft" (non-hardened) tallow, andhardened tallow. Q is CH₂ or N, preferably N, X is ##STR7## wherein T isO or NR₅, R₅ being H or C₁ -C₄ alkyl, preferably H, and R₄ is a divalentC₁ -C₃ alkylene group or (C₂ H₄ O)m, wherein m is an integer of from 1to 8; or X is R₄.

Most preferred softening agents according to the above formula areimidazolines of the following formula: ##STR8## wherein R1 is a tallowgroup.

The softening amines described herein above are suitable for the purposeof the present invention provided they are present in the concentratedsoftening composition in a protonated form; a suitable means toprotonate these amines is described for instance in EP 199 383.

A preferred softening active mixture for use herein is a mixture of 20%to 70% by weight of the softening active of ditallow dimethyl ammoniumchloride (DTDMAC) and 30% to 80% ditallow imidazoline. Preferably, theconcentrated compositions according to the invention comprise from 15%to 25% by weight of the finished product of such a mixture.

In an alternative preferred embodiment of the present invention, thesoftening active comprises a ditallow imidazoline ester such asdescribed herein above (i.e. when T is 0 and R₁ and R₂ are both tallowin the formula above). This embodiment is particularly preferred forenvironmental reasons.

The compositions according to the invention further comprise from 0.3%to 3% by weight of the total composition of a linear fatty alcoholethoxylate of the formula Ro(Etox)n, wherein R is a linear C₈₋₁₈ alkylchain, and n representing the weighted average ethoxylation degree is offrom 3 to 35, or mixtures thereof. Preferred are linear fatty alcoholethoxylates wherein R is a linear chain having from 10 to 13 carbonatoms, and wherein n is from 5 to 10, preferably 8. Preferably, thesecompounds, or mixtures thereof are present at levels of from about 1 toabout 1.5% by weight of the total composition. These compounds arecommercially available from BASF under the trade name LUTENSOL TO®.

The compositions according to the present invention further comprisefrom 0.5% to 6% , preferably from 1.5% to 2.5% by weight of thecomposition of a nonionic hydrophylic polymer, or mixtures thereof. Suchsuitable polymers include polyethylene glycol, polypropylene glycol,polyvinylalcolhol and the like. Particularly preferred is a polyethyleneglycol having a molecular weight of from 300 to 50000, preferably 2000to 10000. In the preferred embodiment herein where the softening activeis a mixture of DTDMAC and ditallow imidazoline, it is preferred to usea polyethylene glycol with a molecular weight of about 4000. In thealternative embodiment where the softening active comprises ditallowimidazoline ester, it is preferred to use a polyethylene glycol with amolecular weight of about 8000.

The compositions according to the present invention further comprisefrom 0% to 2%, preferably from 0% to 0.1% by weight of the totalcomposition of a highly branched fatty alcohol having from 8 to 18carbon atoms, preferably 12 to 14, or mixtures thereof, most preferably13. Branched compounds similar to said higly branched fatty alcohols areoften present in perfumes; thus, the level of said highly branched fattyalcohol to be added to the composition must be adjusted depending on theperfume which is used, if any. Such highly branched fatty alcoholssuitable for use in the compositions according to the present inventionare commercially available from EXXON under the trade name EXXAL®.

The compositions according to the present invention further comprisefrom 0% to 0.5% by weight of the total composition of a linear or cyclicpolydialkylsiloxane of the formula: ##STR9## where R is a C₁ -C₅ alkylgroup and m is an integer of 1 to 500, or mixtures thereof. Saidpolydialkylsiloxanes components are not essential ingredients in thecompositions according to the invention, as the compositions will retainviscosity upon dilution even in the absence of suchpolydialkylsiloxanes. However, several benefits can be obtained fromthese polydialkylsiloxane, including improved stability of the finishedproduct, improved water absorbancy of the treated fabrics. Saidpolydialkylsiloxanes can also be helpful in avoiding the formation offabric softener residues which may occur in the dispenser of the washingmachine. Thus, preferred compositions according to the present inventioncomprise from 0.05% to 0.5%, most preferably from 0.1% to 0.3% by weightof the total composition of the above polydialkylsiloxanes, or mixturesthereof. In the compositions according to the present invention wherethe softening active comprises the ditallow imidazoline ester describedherein above, it is preferred to use a polydialkylsiloxane where R ismethyl and m is about 200. In other compositions, it is preferred to usea polydialkylsiloxane where R is methyl and m is 7. Suitablepolydialkylsiloxanes are commercially available from DOW CORNING underthe trade name 200 fluid, and the preferred polydialkylsiloxanes for useherein are DOW CORNING's 200 fluid 350 CS (R is methyl and m is 203) and5 CS (R is methyl and m is 7).

The compositions according to the invention may additionally comprisesuch conventional ingredients as perfumes, preservatives, germicides,colorants, fungicides, stabilizers, brighteners, opacifiers and thelike, at conventional levels, i.e. up to about 5% by weight of thecomposition.

The compositions in their concentrated form have a viscosity of from 40to 400 cps at 60 RPM shear rate. The compositions according to theinvention can be used directly in the concentrated form, or they canpreferably be diluted before they are used. The compositions accordingto the present invention are meant to be diluted in water, preferably in2 to 3 times their weight of water. In diluted form, the compositionshave a viscosity of from 20 to 60 cps at 60 RPM shear rate, preferably0.30 to 50 cps at 60 RPM shear rate.

Thus, the present invention also encompasses a method for the softeningof fabrics wherein the concentrated fabric softening compositionsdescribed herein above are diluted in water before they are contactedwith said fabrics. In a preferred embodiment of said method, aconcentrated softening composition as described herein above, which hasa viscosity of from 40 to 400 cps at 60 RPM shear rate, is diluted intwo times its weight of water so as to obtain a diluted fabric softeningcomposition having a viscosity of from 20 to 60, preferably 30 to 50 cpsat 60 RPM shear rate, and said diluted fabric softening composition iscontacted with said fabrics in the rinse water.

The compositions according to the present invention are illustrated bythe following examples.

EXAMPLE 1

A composition according to the present invention is made, whichcomprises:

    ______________________________________                                        Ditallow dimethyl ammonium chloride                                                                   7.60%                                                 Ditallow dimethyl imidazoline                                                                         14.20%                                                HCl                     0.82%                                                 Polyethylene glycol 4000 MW                                                                           2.00%                                                 Silicone oil 5CS        0.19%                                                 Lutensol.sup.R  TO8     1.30%                                                 Exxal.sup.R  13         0.08%                                                 CaCl2                   0.20%                                                 Perfume                 0.70%                                                 waters and minors       to 100%                                               ______________________________________                                    

silicone oil 5 CS is a polydialkylsiloxane as defined in thedescription. Lutensol® TO 8 is a linear fatty alcohol ethoxylate, andEXXAL® 13 is a highly branched fatty alcohol, both according to thedescription hereinbefore.

The above composition was made by adding the HCl to a water seat at 60°C.-65° C. To this solution, a molten permix of ditallow dimethylammonium chloride, ditallowimidazoline and Lutensol TO 8 is added atabout 80° C.-85° C., under agitation during about 10 minutes. An aqueoussolution of CaCl₂ is then injected for about 5 minutes. A mixture ofperfume and the silicone oil is then added. The composition is thencooled to room temperature. Finally a 50% solution of the polyethyleneglycol 4000 MW is added.

The composition thus obtained has a viscosity of about 65 cps beforedilution, and 50 cps after dilution in 2 times its weight of water.

EXAMPLE 2

A composition is made which contains:

    ______________________________________                                        Ditallow imidazoline ester                                                                         22.00%                                                   HCl                  1.27%                                                    Lutensol ® TO3   0.12%                                                    Lutensol ® TO5   0.24%                                                    Lutensol ® TO8   1.00%                                                    CaCl.sub.2           0.15%                                                    Polyethylene glycol 8000 MW                                                                        2.00%                                                    Perfume              1.06%                                                    Water & minors       Balance                                                  ______________________________________                                    

EXAMPLE 3

A composition is made which contains:

    ______________________________________                                        Ditallow imidazoline ester                                                                         22.00%                                                   HCl                  1.27%                                                    Lutensol ® TO3   0.12%                                                    Lutensol ® TO5   0.24%                                                    Lutensol ® TO8   1.00%                                                    Exxal ® 13       0.06%                                                    Dow Corning 200 fluid 350 CS                                                                       0.19%                                                    CaCl.sub.2           0.15%                                                    Polyethylene glycol 8000 MW                                                                        2.00%                                                    Perfume              0.90%                                                    Water & minors       Balance                                                  ______________________________________                                    

I claim:
 1. A concentrated aqueous fabric softening compositioncomprising from 10% to 35% by weight of a cationic fabric softeningactive comprising a mixture of ditallow dimethyl ammonium chloride andditallow imidazoline, said composition further comprisingfrom 0.3% to 3%by weight of the total composition of a linear fatty alcohol ethoxylateof the formula RO(Etox)_(n), wherein R is a linear C₈ -C₁₈ alkyl chain,and n representing the weighted average ethoxylation degree is of from 8to 10, or mixtures thereof; from 0.5% to 6% by weight of the totalcomposition of a nonionic hydrophilic polymer selected from the groupconsisting of polyethylene glycol having a molecular weight of from2,000 to 10,000; and from 0 to 0.5% by weight of the total compositionof a linear or cyclic polydialkylsiloxane of the formula:

    R--[--SiR.sub.2 --O--].sub.m --SiR.sub.3

wherein R is a C₁ -C₅ alkyl chain, and m is an integer of from 1 to 500,or mixtures thereof.
 2. A composition according to claim 1 whichcomprises from 15% to 25% by weight of the total composition of saidcationic fabric softening active, or mixtures thereof.
 3. A concentratedfabric softening composition according to claim 1 which consists of from20% to 70% by weight of said softening active of ditallowdimethylammonium chloride and from 30% to 80% by weight of said softening activeof ditallow imidazoline.
 4. A concentrated fabric softening compositionaccording to claim 1 which comprises from 1.5% to 2.5% by weight of thetotal composition of a polyethylene glycol having a molecular weight of4000.
 5. A concentrated fabric softening composition according to claim1 which comprises from 0.05% to 0.5%, preferably by weight of the totalcomposition of said linear or cyclic polydialkylsiloxane of the formula:##STR10## wherein R is methyl, and m is
 7. 6. A concentrated fabricsoftening composition according to claim 1 wherein said softeningditallow imidazoline active comprises ditallow imidazoline ester.
 7. Aconcentrated fabric softening composition according to claim 6 whichcomprises a polyethylene glycol having a molecular weight of
 8000. 8. Aconcentrated fabric softening composition according to claim 6 whichcomprises from 0.05% to 0.5%, by weight of the total composition of saidlinear or cyclic polydialkylsiloxane of the formula: ##STR11## wherein Ris a methyl, and m is
 203. 9. A concentrated fabric softeningcomposition according to claim 1 which comprises from 1% to 1.5% byweight of the total composition of said fatty alcohol ethoxylate of theformula RO(Etox)n, wherein R is a linear C₁₀ -C₁₃ alkyl chain.
 10. Aconcentrated fabric softening composition according to claim 1, saidcomposition having a viscosity of from 40 to 400 cps at 60 RPM shearrate before dilution, and said composition having a viscosity of from 20to 60 cps at 60 RPM shear rate after it has been diluted in 2 times itsweight of water.
 11. A concentrated fabric softening compositionaccording to claim 10 which has a viscosity of from 30 to 50 cps at 60RPM shear rate after it has been diluted in 2 times its weight of water.12. A method for the softening of fabrics wherein a concentrated fabricsoftening composition according to claim 1 and having a viscosity offrom 40 to 400 cps at 60 RPM shear rate is diluted in 2 times its weightof water so as to obtain a diluted fabric softening composition having aviscosity of 20 to 60 cps at 60 RPM shear rate, and wherein said dilutedfabric softening composition is contacted with said fabrics in rinsewater.
 13. A method according to claim 12 wherein the concentratedfabric softening composition having a viscosity of from 40 to 400 cps at60 RPM shear rate is diluted in 2 times its weight of water so as toobtain a diluted fabric softening composition having a viscosity of 30to 50 cps at 60 RPM shear rate.